1. Field of the Invention
The present invention relates to a multi-function Monolithic Microwave Integrated Circuit (MMIC).
2. Description of the Related Art
A multi-function Monolithic Microwave Integrated Circuit (MMIC) is a core part used for a transmitter/receiver (T/R) module for a phase arrangement radar system, and has functions such as determination of one of a transmission mode and a reception mode, shifting a digital phase, and digital attenuation. The multi-function MMIC operates a power amplifier of a T/R module in a transmission mode, and locates a following end of a low-noise amplifier (LNA) of the T/R module to amplify a signal in a reception mode. Therefore, the multi-function MMIC requires a high-power characteristic and a low-noise characteristic.
A Single Pole Double Throw (SPDT) passive switch is used in the multi-function MMIC and the switch determines one of a reception mode and a transmission mode. However, a SPDT passive switch has a signal loss characteristic generally of about −3 to −2 dB. A SPDT passive switch is located at an input and an output of the multi-function MMIC, eventually lowering signal gain of the multi-function MMIC by about −6 to −4 dB.